<template>
  <view
      ref="u-row"
      :style="[rowStyle]"
      class="u-row"
      @tap="clickHandler"
  >
    <slot/>
  </view>
</template>

<script>
// #ifdef APP-NVUE
const dom = uni.requireNativePlugin('dom')
// #endif
import props from './props.js';

/**
 * Row 栅格系统中的行
 * @description 通过基础的 12 分栏，迅速简便地创建布局
 * @tutorial https://www.uviewui.com/components/layout.html
 * @property {String | Number}  gutter    栅格间隔，左右各为此值的一半，单位px  (默认 0 )
 * @property {String}      justify    水平排列方式(微信小程序暂不支持) 可选值为`start`(或`flex-start`)、`end`(或`flex-end`)、`center`、`around`(或`space-around`)、`between`(或`space-between`)  (默认 'start' )
 * @property {String}      align    垂直排列方式 (默认 'center' )
 * @property {Object}      customStyle  定义需要用到的外部样式
 *
 * @event {Function} click row被点击
 * @example <u-row justify="space-between" customStyle="margin-bottom: 10px"></u-row>
 */
export default {
  name: "u-row",
  mixins: [uni.$u.mpMixin, uni.$u.mixin, props],
  data() {
    return {}
  },
  computed: {
    uJustify() {
      if (this.justify == 'end' || this.justify == 'start') return 'flex-' + this.justify
      else if (this.justify == 'around' || this.justify == 'between') return 'space-' + this.justify
      else return this.justify
    },
    uAlignItem() {
      if (this.align == 'top') return 'flex-start'
      if (this.align == 'bottom') return 'flex-end'
      else return this.align
    },
    rowStyle() {
      const style = {
        alignItems: this.uAlignItem,
        justifyContent: this.uJustify
      }
      // 通过给u-row左右两边的负外边距，消除u-col在有gutter时，第一个和最后一个元素的左内边距和右内边距造成的影响
      if (this.gutter) {
        style.marginLeft = uni.$u.addUnit(-Number(this.gutter) / 2)
        style.marginRight = uni.$u.addUnit(-Number(this.gutter) / 2)
      }
      return uni.$u.deepMerge(style, uni.$u.addStyle(this.customStyle))
    }
  },
  methods: {
    clickHandler(e) {
      this.$emit('click')
    },
    async getComponentWidth() {
      // 延时一定时间，以确保节点渲染完成
      await uni.$u.sleep()
      return new Promise(resolve => {
        // uView封装的获取节点的方法，详见文档
        // #ifndef APP-NVUE
        this.$uGetRect('.u-row').then(res => {
          resolve(res.width)
        })
        // #endif
        // #ifdef APP-NVUE
        // nvue的dom模块用于获取节点
        dom.getComponentRect(this.$refs['u-row'], (res) => {
          resolve(res.size.width)
        })
        // #endif
      })
    },
  }
}
</script>

<style lang="scss" scoped>
@import "../../libs/css/components.scss";

.u-row {
  @include flex;
}
</style>
